“I was out in Costa Rica taking photos for my sloth calendar and I was particularly charmed by the Toucan Rescue Ranch and this novel method they have for teaching the sloths how to climb because I've not really come across that before.

“As a zoologist I love their eccentric biology but I think you cannot resist an animal that was born to hug and has a natural smile.”

Peek-a-boo: One of the adorable mammals hangs out in a bucket in San Josecito, Costa Rica (Image: Barcroft)

Sloths in captivity can sleep up to 20 hours a day and, according to a study by Swansea University, the cuddly creatures almost always hang upside down because their organs are fixed to their ribcage.

And Lucy thinks that overworked humans can learn a lot from the relaxed lifestyle enjoyed by sloths.

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She said: “The sloth is an energy-saving totem for the 21st century with much to teach us.

Expert: Lucy holds a tiny baby sloth during her time at the sanctuary in Costa Rica (Image: Barcroft)

“We'd all like to spend more time resting and snoozing, so the sloth is a strangely aspirational animal - we could all do with slowing down, it would be better for us and the planet.

“I think that's why the sloth calendar is so popular, it's a reminder to be more mindful and mellow - plus those smiles are just so adorable.”